So you were attempting to provide charting capabilities on the first generation iPhone? Honestly even now with larger screens, etc I can't imagine that working well on anything smaller than a tablet, and HL7 would only be a selling point to potential partners or investors - 90+% of potential end users wouldn't have a clue about it. You might as well say "our app supports JSON and EDI!"
In 2007 that would have been a dancing bear - amazing to see, but not because of how well it dances.